This invention relates to surface texturing of glass materials and specifically to surface texturing of glass materials induced by locally applied energy. Such texturing may include making bumps, ridges, and all variety of more complex surface features resulting from combinations of these.
The effect of glass swelling when locally irradiated with a laser is known. Small bumps, less than a few micrometers, formed by heating a glass surface with a CO2 laser, have been reported, such as in U.S. Pat. No. 5,567,484, “Process for Texturing Brittle Nonmetallic Surfaces” (1996). Raising larger bumps into shapes defined by an overlying mold has also been reported, such as in U.S. Pat. No. 7,152,434, “Method for Producing Planar Lens and Planar Lens Array” (2006). It would be desirable to be able to raise bumps on a glass surface to significant heights, such as beyond a few micrometers or even as great as 100 micrometers or more, but with fine reproducibility and control of the height such as control as tight as ±100 nanometers, without being limited to the form or shape of a particular mold surface.